双有源桥变换器的优化控制研究OA北大核心

To improve the efficiency of dual active bridge ( DAB ) converters,an optimal control method based on extended phase-shift control is proposed to solve the problems of large inductor current stress and increased return power under the traditional single-phase-shift control,especially under light load conditions.First,the principle of the extended phase-shift control method is elaborated upon in this paper,under which the energy transfer of the DAB converter is controlled by changing the voltage across the inductor through two degrees of freedom of primary-side bridge internal shift and inter-bridge shift.Second,according to the different degrees of freedom,the inductor current stress and transmission power in different working modes are analyzed and deduced.Third,to find the optimal phase-shift combination,the inductor current stress is taken as an optimization objective,and the KKT condition is combined to obtain the optimal extended phase-shift control strategy.Finally,through the construction of a 400 W converter experimental platform,the proposed control method was compared with the traditional control method.It was found that the current stress of the extended phase-shift after optimization was obviously reduced,and the efficiency was significantly improved.